Clinical Comparison of Full and Partial Double Pedicle Flaps with Connective Tissue Grafts for Treatment of Gingival Recession.

STATEMENT OF THE PROBLEM
Gingival recession has been considered as the most challenging issue in the field of periodontal plastic surgery.


PURPOSE
The purpose of this study was to evaluate the clinical efficacy of root coverage procedures by using partial thickness double pedicle graft and compare it with full thickness double pedicle graft.


MATERIALS AND METHOD
Eight patients, aged 15 to 58 years including 6 females and 2 males with 20 paired (mirror image) defects with class I and II gingival recession were randomly assigned into two groups. Clinical parameters such as recession depth, recession width, clinical attachment level, probing depth, and width of keratinized tissue were measured at the baseline and 6 months post-surgery. A mucosal double papillary flap was elevated and the respective root was thoroughly planed. The connective tissue graft was harvested from the palate, and then adapted over the root. The pedicle flap was secured over the connective tissue graft and sutured. The surgical technique was similar in the control group except for the prepared double pedicle graft which was full thickness.


RESULTS
The mean root coverage was 88.14% (2.83 mm) in the test group and 85.7% (2.75 mm) in the control group. No statistical differences were found in the mean reduction of vertical recession, width of recession, or probing depth between the test and control groups. In both procedures, the width of keratinized tissue increased after three months and the difference between the two groups was not statistically significant in this respect.


CONCLUSION
Connective tissue with partial and full thickness double pedicle grafts can be successfully used for treatment of marginal gingival recession.


Introduction
Gingival recession is among the most common periodontal problems in young adults. [1][2] Epidemiologic studies have shown that more than 50 percent of the population have one or more gingival recession sites of 1 mm or more. [3][4] Gingival recession can occur in patients with fair or poor oral hygiene. There is a clear relationship between gingival recession and several risk factors such as dental plaque, calculus, tobacco consumption, tooth brushing frequency, traumatic tooth brushing, high frenal attachment, trauma, and malposition of teeth. [5] Complications of gingival recession include tooth sensitivity, esthetic problems, food impaction, and plaque accumulation leading to root caries, lack of attached gingiva, hyperemic pulp, endodontic problems, difficulties in restoration, and finally tooth loss. [6] Currently, numerous researchers have attempted to treat marginal tissue recession. Treatments for gingival recession include gingival grafting, [7] guided tissue regeneration (GTR), [6] and orthodontic therapy. [8] Using gingival grafts for root coverage has a historical background. However, most studies on this subject were conducted in the second half of the 20th century. [7] Different surgical techniques have been proposed and employed by researchers for root coverage such as laterally sliding flap, [9] free gingival graft, [10] subepithelial connective tissue graft, [11][12] coronallypositioned flap [13][14][15] and GTR. [16][17] Studies showed that the mean root coverage (MRC) was not equal in different techniques. The MRC was reported to be 55-91.2% for coronally advanced flap (CAF), 43-85.3% for free gingival graft and 53.5-87.1% for GTR. [18] The two latest methods applied successfully are subpedicle connective tissue graft and connective tissue with partial thickness double pedicle graft introduced by Nelson and Harris who are the pioneers of these methods, respectively. [19][20] They reported 91% and 97.7% MRT, respectively. The success of Harris's technique was more than that of other procedures described earlier, which seems to be due to the mucosal flap design. [20][21][22] Recent studies have shown that using connective tissue graft (CTG) in conjunction with CAF, modified coronally advanced flap (MCAF) or double pedicle graft (DPG) results in more complete root coverage (CRC) or MRC than the bio-absorbable membranes.
[23] Thus, using CTG in different procedures is still recommended as the most efficient method for covering the denuded root surfaces.
One of the advantages of free connective tissue grafts is the healing by primary intention in the donor site. This is opposite to the healing process of free gingival grafts in which the donor site will be left without coverage, causing pain and discomfort for the patient during the healing process. [23] This randomized double-blind controlled clinical trial aimed to comparing the clinical outcomes of two techniques in order to recommend a simpler and more efficient method.

Materials and Method
Eight patients (6 women and 2 men) aged 15-

Pre-surgical procedures
Phase 1 therapy included oral hygiene instruction, besides scaling and root planning with hand instrument. In case of any occlusal interference, occlusal adjustment was done. Two weeks after phase 1 therapy, the patients were asked to return for oral hygiene monitoring. For this purpose, simplified debris index was used as a measure. If the score was 2 or 3 (soft debris covered more than 1/3 of the denuded root), the surgery would not be performed.
The pre-surgical procedures consisted of preparation of surgical acrylic stent, taking parallel radiographs, intraoral photography from recession sites before, during and after the surgery, and measurements after the surgery. The examiner was a periodontist with 15 years of professional experience. The clinical parameters including recession height, recession width, pocket depth, and keratinized tissue width (KTW) were measured before and after the surgery. Both the patient and examiner were blind to the method of treatment for each mirror defect site.

Surgical procedures PTDPG with connective tissue (test group)
All patients were instructed to use 2 tablets of Ibuprofen  The procedure was the same as that of the test group except for the flap which was mucoperiosteal and was reflected by using a periosteal elevator (Figure 1c-h).

Post-surgical care
All patients were instructed to rinse their mouth with Fisher's exact test showed no statistically significant difference between the two groups in terms of CRC (Figures 2 and 3).     There are some basic differences between these methods, although the similarity in clinical parameters is apparent. It is not technically easy to achieve a fine partial-thickness flap particularly in a thin periodontal biotype. Progressing towards an excessively thin flap increases the risk of serious complications such as perforation and even consequent necrosis of surrounding tissue. The blood supply from the inner part of the flap together with that of the bone is sufficient for survival of the graft and for achieving an outcome comparable to that achieved with a partial-thickness flap reflection. Although the most success rates in root coverage therapy owes to the partial thickness method, this method is immensely technique-sensitive and requires great expertise and skill. On the other hand, performing this type of flap surgery would not be favorable in many cases due to the thinness of available soft tissue and possibility of sudden lacerations. Therefore, clinical comparison of full and partial thickness methods is noble and essential. [20,22] Despite the similarities in clinical parameters and some differences in basis of the techniques, more studies are recommended to evaluate the differences in blood supply of grafts in these methods.

Conclusion
Both FTDPG and PTDPG techniques are effective for treatment of gingival recession and can significantly increase the gingival level. There are no significant differences between these two methods but some factors can influence the result such as using tetracycline hydrochloride as a root conditioner and also the long-term follow-up i.e. more than 6 months. More studies are recommended to evaluate the differences in blood supply and histologically analyze the type of attachment in the treated area.